Try doing some google research.
I'll give you an example - I've been looking at real estate and there is never enough info in the listing - so I google the address looking for another listing with more info.
What I find is the name and phone number of the owner. Then out of curiousity I google the phone number.
What I find is anything on craigslist, court documents, what he does for a living, clubs and associations he belongs to, tax delinquency auctions on his house and on and on. Find out his phone number.
Sometimes the phone number relates to a user name and you can find out forum posts etc. Then guess his password and access his cloud storage and all the pictures he's posted.
Try the address, licence plate, sneak onto his front steps if you see a magazine and get his name and google that.
Slap a magnetic gps on his car and tack him. Rent a drug sniffing dog and see if it alerts on his house. Snap and video him and his visitors and google search the pictures.
Report back when he's arrested.